title: High survival rate of metaphase II human oocytes after first polar body biopsy and vitrification: determining the effect of previtrification conditions.
abstract: OBJECTIVE
  To use metaphase II (MII) bovine oocytes as a model for MII human oocyte cryopreservation and to determine the effect of different previtrification equilibration temperatures, vitrification solutions, zona slitting, and first polar body biopsy on in vitro and in vivo developmental competence of MII human oocytes after the CryoLoop vitrification method.
  
  
  METHODS
  In vitro and in vivo studies.
  
  
  METHODS
  A private infertility clinic.
  
  
  METHODS
  Women undergoing infertility treatment.
  
  
  METHODS
  Metaphase II stage bovine and MII human oocytes underwent first polar body biopsy before cryopreservation in different vitrification conditions, and human oocytes were fertilized by intracytoplasmic sperm injection after warming. The resulting embryos were transferred into women undergoing infertility treatment.
  
  
  METHODS
  Postvitrification morphologic survival, in vitro blastocyst development, and clinical outcome after ET.
  
  
  RESULTS
  The equilibration temperature had a significant effect on cryosurvival of both bovine and human oocytes. High (97%-99%) postvitrification survival was achieved for both MII bovine and human oocytes, and high fertilization (90%-97%) at 35 degrees C to 37 degrees C, blastocyst development (18%-45%), and pregnancy (50%) rates were achieved at 35 degrees C with 5.0 mol/L ethylene glycol + 1.3 mol/L dimethyl sulfoxide for MII human oocytes that underwent first polar body biopsy.
  
  
  CONCLUSIONS
  Previtrification equilibration temperature had a profound effect on the postthaw developmental competence of MII human oocytes in vitro and in vivo. The CryoLoop vitrification of first polar body-biopsied MII human oocytes in the presence of 5 mol/L ethylene glycol plus 1.3 mol/L dimethyl sulfoxide gave the best results in terms of fertilization, embryo development, and implantation rates.
authors.affiliation: Sher Institute for Reproductive Medicine, Las Vegas, Nevada, USA. leventk@sherinstitute.com
authors.forename: Levent
authors.initials: L
authors.lastname: Keskintepe
authors.forename: Yuksel
authors.initials: Y
authors.lastname: Agca
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Sher
authors.forename: Meral
authors.initials: M
authors.lastname: Keskintepe
authors.forename: Ghanima
authors.initials: G
authors.lastname: Maassarani
mesh_terms: D000328:Adult; D000818:Animals; D001706:Biopsy; D002417:Cattle; D002470:Cell Survival; D002478:Cells, Cultured; D015925:Cryopreservation / Q000379:methods; D003451:Cryoprotective Agents / Q000009:adverse effects / Q000494:pharmacology*; D046149:Embryo Culture Techniques; D004624:Embryo Transfer; D005260:Female; D005615:Freezing / Q000009:adverse effects; D006801:Humans; D008677:Metaphase / Q000502:physiology*; D054315:Oocyte Retrieval / Q000009:adverse effects / Q000379:methods; D009865:Oocytes / Q000166:cytology* / Q000473:pathology*; D011247:Pregnancy; D018873:Pregnancy Rate; D020554:Sperm Injections, Intracytoplasmic
chemical_list: D003451:Cryoprotective Agents